Imessage

If Messages in iCloud is enabled, the messages cannot be retrieved. If you're unsure if this feature is turned on, here's how to check: Use Messages in iCloud. If Messages in iCloud isn't turned on, and you have a backup that contains the messages, they can be restored with these steps: Restore your iPhone, iPad, or iPod touch from a backup. Keep in mind, any data that has been put onto your iPhone after the backup was created will be lost. If you have made a backup of the iPhone since you deleted the message, you will not be able to retrieve it either.